[Margh]

Google isn't responsible for software that could glitch out and apply your accelerator directly into a concrete wall.

Like the GP said, physical devices that have a use that is in some way responsible for a human's safety or some element of real risk (cars, medical equipment, fridges, ovens etc.) should have inspectable source code. It need not be open source, just able to be viewed.

That said, if companies are willing to cheat emission schemes they'll probably obfuscate their code to "protect IP" or something.

I'm not saying that it's impossible for cloud software to harm a human, but every example I can think of is fairly contrived and would probably result in somebody reading the code and going "Why does this x-ray query a server for this person's safe dose?"